A program, pill, etc that allows you to eat whatever you wanted and not gain weight would be worth how much?

I went out to lunch the other day with a friend to McDonalds. I ate 2 McDoubles and had a med. chocolate shakes. I had to force down the last bit of the 2nd burger. The McDouble is not a very big burger at all, usually just one and a med. shake is enough to fill me up to the point my hunger is satisfied. Whatever it is that can cause me to be full off so little (and whatever type food I want) and no, I am not wasting away weight wise, I could bottle or make so other people could buy it how much a year do you think it would profit? Eat what you want, get full quicker, and don’t gain weight, how much per dose, treatment, etc. do you believe the average John/Jane Q will spend on it?